Out of the vowels of English alphabet, one letter is selected at random. The probability of selecting the letter 'O' is : 1. 1 2. 3. 4.

Vowels of english alphabet : a, e, i, o, u. Since, there is one letter 'o' in the vowels. ∴ No. of favourable outcomes = 1 P(selecting the letter 'O') = . Hence, Option 4 is the correct option.